Hack against US is ‘grave’ threat, cybersecurity agency says

The U.S. Treasury Department building viewed from the Washington Monument on Sept. 18, 2019. (AP Photo/Patrick Semansky, file)

WASHINGTON — Federal authorities expressed increased alarm Thursday about a long-undetected intrusion into U.S. and other computer systems around the globe that officials suspect was carried out by Russian hackers. The nation’s cybersecurity agency warned of a “grave” risk to government and private networks.